1. Field of the Invention
The present invention relates to a shower apparatus.
2. Description of the Related Art
In the present technical field, a shower apparatus is known which discharges bubbly water by aerating water using a so-called ejector effect. The water flowing into the shower apparatus is distributed to multiple nozzle holes and sprayed therefrom. Therefore, when the spray is aerated, the water flowing into the apparatus is aerated before being distributed among the nozzle holes.
An example of such a shower apparatus is proposed in Japanese Patent Laid-Open No. 2006-509629. The shower apparatus described in Japanese Patent Laid-Open No. 2006-509629 comprises a plurality of nozzle holes provided in a front face of a disk-shaped housing shell and is configured to discharge water flowing in through the center of a rear face of the housing shell by distributing the water to the plurality of nozzle holes. The shower apparatus produces bubbly water by aerating the water which has flowed into the housing shell and distributes the bubbly water to the plurality of nozzle holes formed so as to distribute over the entire front face of the disk-shaped housing shell. Therefore, a turbulence generation/expansion unit is placed in a traveling direction of the bubbly water, causing the bubbly water to change direction by colliding with the turbulence generation/expansion unit and thereby spread over the entire front face of the housing shell.
Another example of a shower apparatus is proposed in Japanese Patent No. 3747323. With the shower apparatus described in Japanese Patent No. 3747323, when a cock such as a hot and cold mixer tap is opened, water is supplied from a hose and passed through an orifice member. Then, the water is mixed with air sucked through an inner suction port open to a decompression chamber installed on a downstream side of the orifice member and maintained under reduced pressure at the given moment. The shower apparatus described in Japanese Patent No. 3747323 produces bubbly water in this way and discharges the bubbly water through a plurality of nozzle holes provided in a shower head. With the shower apparatus, the produced bubbly water proceeds to the nozzle holes by changing direction by hitting a threaded member in a partitioned pipe installed on the downstream side of the decompression chamber as well as inner walls of the shower head installed further downstream.
In spraying a shower using bubbly water produced by aerating water, how to set the feel of the bubbly water hitting a user plays an important role in a feeling of quality experienced by the user who takes a shower. The shower apparatus described in Japanese Patent No. 3747323 is intended to achieve the sensation of water hitting the user intermittently as described in paragraph 0015 of Japanese Patent No. 3747323. It is considered that the term “intermittently” means that finely divided water droplets of nonuniform sizes hit the user. Specifically, the user experiences a sensation of a strong shower if hit by large-size water droplets, and a sensation of a weak shower if hit by small-size water droplets. It is considered that the term “intermittently” expresses a mixed sensation of strong and weak showers experienced alternately by the user.
According to concrete studies conducted by the present inventors, it is presumed that in the bubbly water just produced, water is mixed substantially uniformly with air. Then, the bubbles collide with each other as the produced bubbly water changes direction by hitting the threaded member and the inner walls of the shower head, and it is considered that bubble diameters are nonuniform when the bubbly water reaches the nozzle holes. Consequently, when discharged from the nozzle holes, the bubbly water turns into water droplets of nonuniform sizes, which are considered to achieve the sensation described above when directed at the user.
On the other hand, Japanese Patent Laid-Open No. 2006-509629 does not give any description of properties of the bubbly water discharged from the shower apparatus described in Japanese Patent Laid-Open No. 2006-509629. However, judging from what is described in Japanese Patent Laid-Open No. 2006-509629, it is presumed that the shower apparatus produces water droplets of nonuniform sizes by supplying and discharging bubbly water with nonuniform bubble diameters from the nozzle holes and directs the water droplets of nonuniform sizes at the user, as in the case of the shower apparatus described in Japanese Patent No. 3747323. This presumption is based on the following grounds. First, in the shower apparatus described in Japanese Patent Laid-Open No. 2006-509629, the turbulence generation/expansion unit is placed in the traveling direction of the bubbly water, causing the bubbly water to change direction by colliding with the turbulence generation/expansion unit. In view of the configuration, it is considered that similar nonuniform bubble growth takes place in the shower apparatus described in Japanese Patent No. 3747323 and that resulting water droplets of nonuniform sizes are directed at the user.
Under these circumstances, the present inventors intended to provide a shower apparatus which enables spray of a shower with a comfortable voluminous feel as if one were showered by large drops of rain. In contrast, the above-described conventional techniques achieve the sensation of nonuniformly-sized water droplets hitting the user as described above. Thus, the conventional techniques do not provide spray of a comfortable shower with a voluminous feel as if the user were showered by large drops of rain.
To provide spray of a shower with such a new feel, the present inventors paid attention to the state of bubbly water in nozzle holes and just after discharge from the nozzle holes. In the nozzle holes and after discharge from the nozzle holes, the bubbly water is in a state of gas-liquid, two-phase flow in which two different types of fluid—gas and liquid—coexist and move in the same flow conduit. Therefore, the bubbly water is considered to be flowing in any of the typical flow patterns of bubble flow, slug flow, and annular flow. Since these flow patterns differ in the manner of bubble inclusion, it is considered that they also differ in the manner of fine division after discharge from the nozzle holes. Therefore, the present inventors presumed that with the conventional techniques, since the bubble diameters in the bubbly water supplied to the nozzle holes are nonuniform, the bubbly water is discharged under the coexistence of bubble flow, slug flow, and annular flow, resulting in the sensation of nonuniformly-sized water droplets hitting the user. Thus, the present inventors considered it important to control the bubble diameters of the bubbly water supplied to the nozzle holes to be uniform.
However, water is normally supplied to a shower apparatus through a single supply port. Furthermore, bubbly water is produced by aerating the water supplied through the single supply port. Although water is supplied to the shower apparatus in this way, multiple nozzle holes are provided. Therefore, the bubbly water is stimulated when being distributed to the nozzle holes by changing the direction of the bubbly water. This makes it extremely difficult to discharge the water from the nozzle holes without causing the air bubbles to grow.